Beech C-45 conundrum

[bobmig]

I've been looking at lots of Beech C-45s/SNB photos lately and have noticed that some aircraft have two small round windows on the starboard side, some have only one. I've tried to find a common denominator, but there doesn't seen to be any. Is it a local mod?… A particular version of the aircraft?… or what? Any ideas?

Bob

 

[Admiral Puff]

I've had a run through Parmerter's bible on the Beech 18 and the feature doesn't rate a special mention. It seems to be more common on late war/post war production aircraft, but that's not necessarily a hard and fast rule - some have one, others two, some none at all, others have one or two on the port side instead/as well. I suspect it's down to individual customer requirements.

[JWM]

a toilet windows?

[Greenshirt]

One may be for a toilet, the other for a galley. 

[bobmig]

It's a little small to need a galley! I'm starting to think it may have some relation to its role, e.g. personnel transport vs nav trainer. I think I'll start searching for interior views and see if they give any clues.

[72modeler]

After doing some research of the civilian and military variants of the Twin Beech, it appears that were 7,8, and 9 passenger versions produced; the military impressed many of these for service, and at some point after the war, existing C-45's were remanufactured to a standard fit, which was designated C-45G and C-45H, IIRC. The fuselages on the civil and military versions that had the 8 and 9 passenger capacity were extended  six inches and appear to have two round windows installed  on each side of the aft fuselage, which might account for the difference in the number and type of windows seen in photos. I guess your best bet, as always, is to use a photo of the one you want to build as a reference. Good luck! (Sure wish we had a decent state-of-the-art 1/72 kit!)

Mike

 

http://www.skytamer.com/Beechcraft_18_C-45H.html

[Graham Boak]

I haven't been able (lack of sources) to study the Beech 18 is quite the depth I'd like, so may be treading on uncertain ground here.  However, I think the fuselage increase of six inches may be reflecting the slightly longer nose introduced on the C-45F rather than any increase in the cabin length.  Extending the rear fuselage would be noted as a distinct sub-type, and I've found no reference to this.  Six inches would be insufficient for an extra row of seats, and not make much structural sense.  However, it would provide a significant aerodynamic change in added stability and control authority, which does not seem to have been required.  Yet the second round window was present on the 1940 JRB-1, though I haven't seen (very limited search!) any other early examples.  Given that later aircraft can be seen with and without, I suspect this is more likely linked to being a toilet window, late aircraft being more likely to have such.  That it is aft of the door is probably a hint.  This doesn't exclude earlier examples having such a feature.

 

Postwar upgrades to a single variant (the C-45G) imply a single source of fuselage sizes: the C-45H being a variant with different engines.  Postwar extended fuselage variants did exist of course, but rather more than six inches in length.  The postwar Super 18 did have a 6in increase in cabin height, but this doesn't seem to have affected anything aft, and as conversion kits were introduced for all C-45G/H examples this tends to point to a single fuselage size.  

 

Do your sources include dimensional data for the variants with any fuselage extension?  Mine don't give a length for anything earlier than the D.18S.  The limited number of earlier versions, and their longer use, would tend to rule them out of later upgrades, the arguments above would not apply.  The other key change from the initial design was the (prewar) introduction of more powerful engines, so a little extra tail authority could be desired.

Edited April 2, 2017 by Graham Boak
Consideration of early design changes

[bobmig]

As I understand it post-war models starting with the E18 had a fuselage with an additional 6 inches in height to provide more headroom in the cabin. If you look at photos you can see the difference. Some earlier models were also rebuilt to these specs, but I don't believe it was done to military aircraft. Sources I've read state that models starting with the C-45F had a longer nose, though I don't know how much longer. Many post-war civil versions had noticeably longer, more pointed noses. Below: C-45G (top) and Beech E-18 (bottom)

Bob

[72modeler]

10 hours ago, Graham Boak said:

I haven't been able (lack of sources) to study the Beech 18 is quite the depth I'd like, so may be treading on uncertain ground here.  However, I think the fuselage increase of six inches may be reflecting the slightly longer nose introduced on the C-45F rather than any increase in the cabin length.  Extending the rear fuselage would be noted as a distinct sub-type, and I've found no reference to this.  Six inches would be insufficient for an extra row of seats, and not make much structural sense.  However, it would provide a significant aerodynamic change in added stability and control authority, which does not seem to have been required.  Yet the second round window was present on the 1940 JRB-1, though I haven't seen (very limited search!) any other early examples.  Given that later aircraft can be seen with and without, I suspect this is more likely linked to being a toilet window, late aircraft being more likely to have such.  That it is aft of the door is probably a hint.  This doesn't exclude earlier examples having such a feature.

 

Postwar upgrades to a single variant (the C-45G) imply a single source of fuselage sizes: the C-45H being a variant with different engines.  Postwar extended fuselage variants did exist of course, but rather more than six inches in length.  The postwar Super 18 did have a 6in increase in cabin height, but this doesn't seem to have affected anything aft, and as conversion kits were introduced for all C-45G/H examples this tends to point to a single fuselage size.  

 

Do your sources include dimensional data for the variants with any fuselage extension?  Mine don't give a length for anything earlier than the D.18S.  The limited number of earlier versions, and their longer use, would tend to rule them out of later upgrades, the arguments above would not apply.  The other key change from the initial design was the (prewar) introduction of more powerful engines, so a little extra tail authority could be desired.

Graham,

 

Jeez, Louise! I misread the text in the link I posted- the 6-inch increase was in height, not length! I'm wiping the egg off of my face as I type this. Thanks for setting me straight; I tend to agree with your galley window assessment, but wonder why the need for the window, except maybe to avoid having to install and wire a lavatory light? Can't imagine standing up and watching the scenery go by! I do remember when my Dad was stationed at Myrtle Beach and Shaw AB, both in South Carolina, as well as Dyess AB in Texas, there were always a couple of highly polished C-45's used as hacks, taxis, or for desk types to use to get their flying hours in to receive  flight pay! Can't afford a proof-reader, but maybe I need to look for one- sorry if I messed anybody up!

Mike